Electrical problem? Help!

Installed 2 450RMS subs, and an AQ1200D amp.
Everything seemed to work fine for a while, until I started thinking that the system should be louder than it is. I started doing DMM tests on the system, and sometimes it would drop down to like 11.xx, or even high tens at some point.

I went out and bought an Optima Red Top, and did the big three. Measured the voltage at the amp, and that thing wouldn't drop below 13 no matter how hard it hit. Now, i'm having the same issue, but not as low. It still will drop down to like 11's or low 12s, and it seems like the bass output isn't nearly as much as it was before. It clips with minimal bass.

Do I need a new alternator? I went to autozone and had them "Test" it, but I didn't have the system on for the test. it said it was "ok."

Re: Electrical problem? Help!

get the red top checked u could have cracked one of the lead plates, cores what ever they are. even though it is a sealed agm battery it still is a lead acid battery, just with the acid absorbed in the glass mat. they can still have bad cells

Re: Electrical problem? Help!

i had a good 7 years on my redtop before i replaced it. it was still fine, i just wanted a new battery. always had systems running on it. red tops are made as a starting battery - which is what the main battery should be. i've heard more issues with yellow tops being used as a main battery and not being properly charged. not an issue with the battery as it is with the user - call it operator error - batteries need to be charged regardless of who makes them. optima's problem is that they are well known and used by plenty of people who don't know any better. a battery failure is 99% operator error and 1% manufacturer error.

sounds like you aren't charging your battery. your alt may be fine but too small to handle the load, so you drive around draining your battery and never actually fully charge it.

Re: Electrical problem? Help!

well i would say it should be enough. i would check all power connections to be sure they are all tight and good. i see you had the same issues with both batteries, and its coming and going for no reason. could be a loose connection under the hood. and if your constantly dropping into the low tens voltage wise, i would calm down on the volume as you could possibly blow the amp from under voltage.

and red tops are for starting, you would need a yellow top, but the red will"work". personally i would bring it back and get a yellow top, put the old battery back under the hood, and run the yellow top in the back.

if your alternator is causing you fits, the battery may make up for the amperage you don't have. also a 1200 watt amp should use about 90 amps of current. 40 % of your alternator is most likely being used by the cars systems and etc, so that's about 50 amps, leaving you 70 amps for your car audio. you can see @ peak amperage draw you don't have enough without a second battery, and i really wouldn't rely on the starting battery to make up the amperage you don't have.

so, either bring back the red top, and put the yellow in back, or put old battery under hood, and red top in back. if all of the above doesn't help, upgrade to a larger alternator. and check all wiring connections including alt to battery etc to see if they are loose.

Re: Electrical problem? Help!

Well, trying to charge a second battery with a possible last-crutch alternator isn't a good idea. Since the system wasn't dropping once I got the new battery, it's leading me to believe the issue lies within the alternator. I've checked all of the connections multiple times, and ensured that the grounds are tightly fastened and the paint is sanded off.